Assembly of two and three pole circuit breakers



Feb. 2, 1954 w. H. EDMuNDs ASSEMBLY 0F Two AND THREE POLE CIRCUIT BREAKERS Filed Nov. 28, 1951 5 Sheets-Sheet l BYk--l Feb. 2, 1954 w. H. EDMUNDS 2,668,206

` ASSEMBLY OF' TWO AND THREE POLE CIRCUIT BREAKERS Filed Nov. 28, 1951 5 Sheets-Sheet 2 I N VEN TOR. duwen/iena DMW/VPA' ASSEMBLY oF Two AND THREE POLE CIRCUIT BREAKERS v Filed Nov.l 28, 1951 Feb. 2, 1954 w. H. EDMUNDS 5 Sheets-Sheet 3 mm w Feb. 2, 1954 w. H. EDMUNDS' 2,668,206

ASSEMBLY OF TWO AND THREE POLE CIRCUIT BREAKERS Filed Nov. 28, 1951 5 Sheets-Sheet 4 IN VEN TOR.

du 4 ma #memo Enma/v 05 Feb. 2, 1954 w. H. EDMuNDs ASSEMBLY OF TWO AND THREE POLE CIRCUIT BREAKERS Filed Nov. 2a, 1951 5 Sheets-Sheet 5 Patented Feb. 2, 1954 ASSEMBLY F TWO AND THREE POLE CIRCUIT BREAKERS William H. Edmunds, Havertown, Pa., assignor to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Application November 28, 1951, Serial No. 258,615

(Cl. 20D-88) 13 Claims.

My present invention relates to multi-pole circuit breakers principally for lighting circuits and more particularly it relates to a method of assembly of this type of circuit breaker.

Circuit breakers used principally for lighting circuits instead of fuses must satisfy two very important requirements, namely, they have to be small and they have to be inexpensive.

Small circuit breakers having two or three poles have been described in applications Serial Nos. 241,018, iled August 9, 1951, and 254,065, iiled October 31, 1951.

This type of small circuit breaker could be made quite inexpensively if the labor necessary to acsemble them could be reduced to a minimum.

In previous methods of assembling these types of circuit breakers, all the parts of the multi-pole circuit breaker were introduced in the housing of the circuit breaker from the front of the circuit breaker and were iixed in their positions by means of screws, nuts and bolts or rivets.

It is evident that in this type of assembly great care must be exercised that all parts occupy exactly their correct position. More labor was involved in that the assembler had to secure these parts to the housing.

1t is further evident that different housings would be needed for single pole circuit breakers, for two-pole circuit breakers and for three-pole circuit breakers.

My invention overcomes this difficulty by using a different system of assembly, a system commonly known as pancake assembly. Pancake assembly means that all parts of the circuit breaker instead of being mounted or introduced in the housing from the front are instead introduced in the housing from one side. The pan.- cake arrangement permits 'building each pole separately and adding the necessary tie links between the poles to make a common trip and operating breaker as the assembly progression continues.

A two-pole breaker, for example, would be made of a single housing with one operating handle, one cover plate on each side of the housing, and the housing would be a moulding with openings on the opposite side covered by the cover plates and divided into two circuit breakers by a central wall.

A three-pole circuit breaker instead could be made by connecting together the above-described two-pole breaker with a single pole circuit breaker moulding. Since each moulding permits side assembly of each pole, the pole mechanism and 2 the other current carrying parts are completely assembled as a unit.

The base or mounting mouldings have openings for common operating parts including the handle, cradle tie members and common tripper bar.

The two-pole breaker can be assembled in a panelboard or load center in the same space as two single pole breakers while the three-pole breakers will occupy the same space as three single pole breakers.

One of the cover plates used on 'the twoand three-pole breakers is exactly the same, thus permitting considerable versatility.

The mouldings for the twoand three-pole circuit breakers can be so shaped that every part of the circuit breaker can be slid into its place without any need for fixing it to the circuit breaker housing except for a few parts.

It is thus seen that cover plates in this type of circuit breaker will have two functions, that of protecting the circuit breaker equipment and that of securing each part of the circuit breaker in its correct position.

It is evident that since the assembler of this type of circuit breaker only has to slide the neces-- sary parts in their proper places, the amount of labor required for assembling this type cf circuit breaker is considerably less than in previous types, thus making it possible to manufacture circuit breakers at a substantially lower cost.

The main object of my present invention is, therefore, a method for easily assembling multipole circuit breakers from the side instead of from the front.

Another object of my present invention is the provision of means whereby all parts of a multipole circuit breaker can be slid into appropriately shaped openings of a, circuit breaker moulding.

A further object of my present invention is a method of assembling multi-pole circuit breakers that permits building each pole of the multipole circuit 'breaker separately and adding the necessary tie links between the poles to make a common trip and operating breaker.

The foregoing and many other objects oi my invention will become apparent in the following description and drawings in which:

Figure 1 is a front view of a two-pole circuit breaker incorporating my present invention.

Figure 2 is a cross-sectional view taken on line 2--2 of Figure 1 looking in the direction of the arrows showing only the moulding ready to receive the parts of the circuit breaker.

Figure 3 is a cross-sectional View of the circuit breaker of Figure 1 taken on line 3-3 oi Figure 1 looking in the direction of the arrows showing the circuit breaker moulding with all circuit breaker parts in place.

Figure 4 is a cross-sectional View taken on line 4 4 of Figure 3 looking in the direction of the arrows showing the moulding and the circuit breaker parts.

Figure 5 is a cross-sectional View taken on line 5-5 of Figure 3 looking in the direction of the arrows showing only the moulding ready to receive the parts of the two-pole circuit breaker.

Figure 6 is a front View or a three-pole circuit breaker incorporating my present invention..

Figure 7 is a cross-sectional view taken on line l-l of Figure 9 looking in the direction of the arrows showing only the moulding ready to receive the parts of the three-pole circuit breaker.

Figure 8 is another cross-sectional view taken on line 8-8 of Figure 9 looking in the direction of the arrows showing the circuit breaker moulding with all circuit breaker parts in place.

Figure 9 is a cross-sectional 'view taken on line S-Sl of Figure 6 looking in the direction of the arrows showing the circuit breaker mould ing with all circuit breaker parts in place.

Referring now to Figures 1 and 2 showing, respectively, the front ci a two-pole circuit breaker and the base molding of a twopole circuit breaker ready to receive the parts of the circuit breaker, a base iii, usually a plastic molding, is so shaped that practically all the components of the circuit breaker can ce easily slipped in place and can be secured thereby the application of cover plates ii and i2 without using any other securing means such as screws, bolts, nuts, etc., the cover plates ii and l2 being secured to housing It! by means of rivets or other means engaging openings l5 of housing it.

Referring now to Figures 4 and 5, it is there Seen that a two-pole circuit breaker molding has two recesses, a relatively larger recess and a smaller recess 72|. These two recesses and 12| are divided by a plastic separating wall '|22 which is an integral part o molding iii.

Recess '|26 shown more clearly in Figure 5 houses all the component parts of one pole of the two-pole circuit breaker1 while recess 'iti houses all the component parts or the second pole of the two-pole circuit breaker as shown in application Serial No. 254,065, iled October 31, 1951.

Plastic surfaces '|23 on the two sides or wall 'F22 have the conguration shown in Figure 2 so that all the component parts of one pole of this circuit breaker can be slipped into place at the beginning of the assembly operation.

Referring in fact to Figures 2 and 3 showing the molding IG with and without the component parts of the two-pole circuit breaker, stationary contact assembly consists of a Contact button 2|, welded or in any other appropriate way secured to the bent end of a conducting member 25. Member with Contact button 2| is slidably mounted in an appropriately shaped recess 2S of molding It, that is, member can be slid in place in housing l@ when cover plate is removed. The other end or conducting member 25 has a central opening 3i threaded inside and engageable by a screw 35. One wire of one phase of the circuit (not shown) can be secured to the circuit breaker by means of screw and extension 35i of contact member 25. The other wire of the same phase is se- (Eil cured to the circuit breaker at terminal 3l. Terminal 3l consists of a screw 38 engaging an opening it in an angularly shaped contact member Gil.

Contact member s of rectangular cross-section is secured to housing i@ by means of a screw (il engaging through an appropriate opening 42 of housing it a threaded opening [i3 in contact member d. rBhe other end of contact member lil is provided with a screw which engages member #it at one end oi thermally responsive member The other end oi thermally responsive member de is connected by any appropriate means, for example, soldering to a flexible conductor or pigtail A support an integral part of contact member 9, consists oi two extensions 53 and Sil, one on each side of thermally responsive member 15. Both supports 53 and extend beyond thermally responsive member le and carry at their farthest end a pin A coil spring di! around pin has one end di against a protruding portion 52 of housing lil and its other end 63 biases a latch carrying member t5.

Latch carrying member consists of a thin metallic leaf @t approximately U-shaped having at one end extending arms @i with openings t3 which are engaged by pin so that member i can rotate around pin 55. The other end of member t5 is bent and has a U-shaped portion with aligned openings carrying tripper bar il). Tripper bar l@ is held in place by a bent finger '2| cut from the metallic leaf Gi.

Tripper bar it is an insulated bar common to the two phases of the circuit breaker; that is, tripper bar 'it extends from the phase of the circuit breaker now under consideration to the second phase of the same circuit breaker as hereinafter described.

Trip lever t5 is further provided with an armature l2 which is secured to a trip lever 55 by any suitable means, 'for example, a rivet. Armature l2 is the movable part of the fault current responsive magnet l5 which consists o a rectangular piece of metal with a central recess 'it to receive thermally responsive member i5 to which it is also secured by means of a rivet. The same rivet that secures armature 'i2 to trip lever 65 can be used` to secure latch lid to trip lever 65.

Thermally responsive member lili and magnet l5, as is quite evident, are designed to operate at different values of fault currents. For example, when a fault current is relatively small, the thermally responsive member i6 will operate to open the circuit breaker as hereinafter described. If, on the other hand, the fault current is relatively high, magnet 'i will come into operation before thermally responsive member t and open the circuit breaker. This is important in that by this means thermally responsive member 46 is protected against very heavy currents which could permanently distort and damage biinetallic member llt and also affords instantaneous trip operation.

Latch Si? carried by trip lever 65 engages a hook-shaped cradle and more precisely latch 8@ engages one end it of cradle 85. Cradle 85 is pivoted at the other end 8! by means of a pin 83 engaging an opening t9 in cradle S5 and an aligned opening 9@ in a, boss ti oi molding it.

Cradle 85 or" the rlrst phase moves together with cradle |85 of the second phase since the two cradles 85 and E35 are connected together by an insulating tie bar 95. ITie bar actually consists of a center insulating sleeve 96 and two lateral insulating sleeves 91 and 98. C'entral sleeve 96, cylindrical in shape, has two recesses 99 and Hill, one at each end of cylinder ed. Lateral sleeves 91 and 95 instead have an axial or longitudinal opening lill and litt, respectively.

Cradles 85 and |85 both have an open Ict. Each opening it is engaged by the cylindrical extension |54 of 'a cylindrical pin |05. A metallic hollow cylinder IBS is slid on the extension It and riveted there. Thus, cradles S5 and |85 are clamped to pins |85 and will move with pins It. Sleeves 91 and 9S are placed around pins itt, While sleeve 95 is placed around the hollow cylinders |66, thus completely insulating one phase from the other and making at the same time a mechanism strong enough to resist damage produced by repeated opening or closing operations.

It is quite evident that since the function of extension HM of pin i635 is only that or moving cradles 85 and IE5 together and since covers il and |2 are here used to keep the slidably mounted parts in their places, it is not really necessary to rivet hollow cylinder |56 to pin 'm5 and thus clamp cradle 85 or |85 since the same effect can be had if these parts were all siidable with respect to each other.

Pigtail 50 connected on one side to thermally responsive member d6 is connected on the other side to movable Contact arm lit. Movable contact arm ||ll is approximately U-shaped or is shaped like a tuning fork, the lowest part l ii of movable contact member il@ carrying an electrical contact H2. The two extensions 25 or ccntact arm IID can rotate in groove lili ci handle molding |20. An over center tension spring |25 is connected on one side to movable contact arm |||l through an opening lill in contact arm lill and on the other side to cradle 35 through an opening |2'l in cradle G5. Cradle 85 is further provided with a pin l which engages a slot lSI of a contact kicking member |35. Contact kicking member |35 is pivoted around pin |3e which engages an opening |31 in contact kicking member 535 and an aligned opening, not shown, in molding it. Contact kicking member' l5@ is provided with an extension |39 at the end oi the contact kicking member |35 opposite that at which it is pivoted.

The function of the contact kicking member |35 is to assist the initial opening operation caused by a fault current; more speciiically, it provides a means for kicking the movable contact away from the complementary contact when the spring has been moved lover center during automatic opening. ln other words, kicker |35 prevents contact i2 from sticking to the stationary contact 2| at fault currents, thus preventing welding o the contacts.

Manual operating handle molding It@ operates simultaneously both contacts of the two phase circuit breaker under consideration. lt has, therefore, a single handle ide with an integral axially extending member Elli This axial member |4| has two pivots la? and M3, one on each side of axial member Ifii, both integral parts of molding |25. Axial member Il has two pairs of fulcri Ill and |56 of which, as previously cxplained, fulcrum I ld is for movable contact member I0, while fulcrum 55 is for movable contact member |55 of the second phase of the twophase circuit breaker under consideration. Molding |25 is also provided with two extensions led, one on each side of iulcrum IIB operable to en.- gage a reset pin |56 carried by cradle 85 in an appropriate opening |51 located between pin |30 and spring opening |21 in cradle 85.

Referring now to Figures 3 and 4, it is there seen that the two phases use practically the same parts except in their common operating mechanisms for both automatic and manual operation.

To be more speciiic, the second phase fault current responsive means consists of a thermally responsive member N6. The free end of thermally responsive member 246 is connected to pigtail or flexible conductor 250. Thermally responsive member 24S further carries rigidly secured to it an approximately U-shaped metallic member (not shown). The U-shaped metallic member constitutes the magnet for the magnetic fault current responsive means when current flows through thermally responsive member 246.

A leaf spring (not shown) is riveted to one end of thermally responsive member 266. This leaf spring extends beyond the free end of thermally responsive member 246 and to the other side of thermally responsive member 245. Leaf spring 265 also carries the armature, not shown, for the magnet.

As it is evident from this description, no latch is provided for this second section phase, that is, only the first phase or the phase which has the manual operating means is provided with a latch 8c for latching cradle 85.

When a fault occurs in the second phase, either thermally responsive member 2&5 or its magnet will operate and will engage and move tripper bar 10 in such a direction as to unlatch cradle 85 irom latch 8E) of the first phase, but since cradle |65 of the second phase moves together with cradle of the iirst phase as previously described, cradle |85 will rotate together with cradle 85 around its pivot pin, not shown.

This movement of cradle |85 will carry spring 315 of the second phase over center with respect to movable contact arm |55, thus opening the electrical contacts between the movable Contact and stationary contact not shown.

The second phase is also provided with a contact kicking assembly (not shown) which operates in the same manner as kicking assembly |35 of the first phase.

Each phase is further provided with an arc extinguishing chamber 360 having a plurality of conducting arc extinguishing plates Sill. One of the two chambers 30G is located between the stationary Contact 2| and movable contact I i2, while the other chamber 3mi of the second phase is located between the corresponding contacts o the second phase. As above-mentioned, all the other parts of this second phase are the same as those used in the iirst phase.

Recess 12| of the same molding I0 houses all the component parts of the other pole of the twopole circuit breaker under consideration as shown in application Serial No. 254,065, led October 3l, 1951, and the assembly operation will then be performed rst by placing molding Ill on its side and mounting all the component parts in recess l2!) which also has the coniiguration shown in Figure 2.

All parts corresponding to this pole of the twopole circuit breaker are slid into place into the appropriate openings as shown in Figure 2.

When all the component parts of this phase of the two-pole circuit breaker are mounted in the recess 120, cover plate is placed over recess 12. After this, the molding VIll is reversed and the component parts of the other phase of the two-pole circuit breaker are mounted in recess 12|.

As previously mentioned, the component parts mounted in recess i125 are slightly different from those used in recess '|2I in that the operating mechanisms (handle |45 and latch 8G, see Figure 3) are housed in recess T25. A tie bar 95 is slid through opening in center wall T22 to secure together the two cradles 55 and |85 of the twopole circuit breaker. The common tripper bar 19 is also slid through a second opening 152 in separating wall "22 so that the operation of any one of the two thermally responsive elements 46, 245 or magnets 15 (shown for only one phase) will cause both poles to trip open.

After having placed all the component parts in recess 12| of housing l5, as shown in Figure 3, the second cover plate l2 is placed on recess 12| and appropriate rivets are then slid through holes in the two cover plates i and l2 and appropriate holes in housing Ill so that the cover plates Il and I2 are rigidly secured to housing I5, and all the component parts of the two-pole circuit breaker are secured in their respective positions by the two cover plates and l2.

Referring now to Figures d, 7, 8 and 9 showing the i'ront, a section of the housing and two sections of a three-pole circuit breaker incorporating my invention, it is seen that housing 4|@ of the three-pole circuit breaker actually consists of a housing 1i for a two-pole circuit breaker and a housing 1|2 for a single pole circuit breaker mounted side by side. Cover plates 4H and 4|2 are secured to housings 4H] and H2 to keep all the component parts in place.

All the component parts for each of the three phases are the same as those described for thc two-pole circuit breaker except for the elements common to all three poles.

In fact, handle molding 525 consists of a handle 548 and in a direction perpendicular to said handle 545 two extensions 54| similarly shaped, one on each side of handle 549. At the ends of these extensions 54| are two cylindrical extensions 543 which by engaging appropriate openings 544 of cover plates 4| I and 41' 2 make possible the rotational movement of molding 529 around cylindrical extensions 543, Members 54| actually constitute a single piece having three pairs of grooves 518 in which arms 5|5 of movable contact arms 5 l5 can rotate.

The central phase in the three-pole circuit breaker corresponds to the rst phase of the twopole circuit breaker above described in that it is the only phase provided with a latch 455 for its cradle 485. This center phase instead of having a leaf spring has, similarly to the first phase of the two-pole circuit breaker, a metallic leaf member 455 (corresponding to member |55 of Figure 4) which at its end 486 carries the tripper bar 410.

Tripper bar 415 can be operated by the center phase now under consideration by means of the thermally responsive means 446 or Should the fault current be very high by means of a magnet 415 secured to thermally responsive member 445 and an armature 415 secured to leaf member 46B.

Here tripper bar 4l@ extends through opening 462 in phase separating walls 460 of moldings 1| and 122 into the two lateral phases. Tripper bar 41! extends suiliciently so that any one of the two leaf springs 565 operated by thermally responsive members (not shown) similar to members 246 or magnets (not shown) will engage tripper bar 410 and unlatch the central phase 8 latch 48B from engagement with the Central cradle 435.

Central cradle 485 now free from engagement with latch 480 will rotate around its pivot (not shown). Rotation of central cradle 485 around the pivot will produce similar rotations in the other two cradles 585 since all cradles are connected for simultaneous movement by tie bar 495.

Tie bar 455 extending through openings 5|3 of phase separating walls 469 into the other two phases, actually consists of two center insulating sleeves 455 and two lateral insulating sleeves 491 and 453. Central sleeves 496, cylindrical in shape, have two recesses 499 and 50E] one on each end of insulating cylinder 496. Lateral sleeves 451 and 498 instead have axial or longitudinal openings 5i!! and 592, respectively.

Cradles 485 and 585 all have an opening 4503 near the ends 486 and 585, respectively. Each opening 553 is engaged by a cylindrical extension 554 or" a cylindrical pin 595 and a metallic hollow cylinder 556 is then slid on the extension 504 and riveted there.

Thus, cradles 485 and 555 are clamped to these pins 595 and will move with pins 555. Sleeves 451 .and 49B are placed around pins 595, while sleeves 499 are placed around the hollow cylinder 555, thus completely insulating one phase from the others and making at the same time a mechanism strong enough to resist damage produced by repeated opening or closing operations. Sleeves 491 and 498 and pins 555 are kept in place by the two cover plates 4|| and 4|2, one on each side of the three-pole circuit breaker.

As above mentioned, rotation of central cradle 455 produces through the bar 495, similar rotations in the other two cradles 585.

Rotation of cradles 435 `and 555 brings the springs 525 and '|25 respectively, over center with respect to the movable contact arms 5|@ and lill, respectively, thus opening the contacts o f the center phase and also the contacts (not shown) of the other two phases simultaneously.

The assembly process is made in the following steps: First, all the component parts forming phase A of the three-pole circuit breaker are slipped in their respective positions in recess H9. Surface of housing 4H? has the configuration shown in Figure 2 to permit the operator to slide practically all the component parts in their appr-opriate positions without any need for securing these parts with screws, bolts and nuts, etc.

After all the component parts have been slid in place in recess H9, a cover plate 4|?! is placed on recess 'H9 to close recess 1|9. The two-pole scction 1li of housing 415 is then reversed and the component parts of phase B are then slid in place in their correct positions in recess 139. This section of housing 1|! is also provided with a surface 13| having the configuration shown in Fig. 2 so that all the component parts of phase .B can be easily slid in place and positioned there with practically no need for securing means.

Section 'H2 o1" the single pole circuit breaker is then mounted on recess 139 to close recess 130.

When housing section 1|2 is mounted on housing section 1H, it may already have the component parts of phase C mounted in its recess 14|) and secured thereto by means of another cover plate 4| The three phases are thus seen to be separated by two walls 455, all provided with appropriate openings so that tie bar 495 and trlppel' bar 41B common to all three phases can be positioned in housing 4|.

As shown in the previously mentioned application Serial No. d65, filed October 31, 1951, the center phase B is provided also with a manual operating mechanism and a latch similar to latch St shown in Figure 3 for the two-pole circuit breaker. Actually, the center phase B of the three-pole circuit breaker has all the component parts shown in Figure 3 for the two-pole circuit breaker.

After placing the cover plates dii and dit housings iii and lili, thus forming comp1 housing die, rivets are passed through priate openings in cover lili and housing titl, thus securing cover iii and 452 to housing dill.

To summarize the above, in the case ci the twopole circuit breaker, first all the component parte of the principal phase are mounted in recess 'i' t; then cover plate il is placed over recess After this, the molding ii is reversed 'and the component parts of the second phase of the two-- pole circuit breaker are mounted in recess li. Finally, the second cover plate l is secured to housing lil, thus completing the two-pole circuit breaker'.

In the case ci? the three-pole circuit breake ince the housing iid of the three-pole circuit breaker is actually formed by the superposition of housing 'il I of the two-pole circuit breaker and housing 'H2 of the single pole circuit breaker, all the component parts for the single pole circuit breaker are mounted in housing lil. The interconnecting links consisting or" the tie bar L95 and tripper bar Mii are then placed in their positions extending from one cover plate iii to the other cover plate dit. Cover plates iii and LliZ are then placed over recess lis ci housing lil and the other over recess lili? of housing lia.

In the foregoing l have described my invention solely in connection with specific illustrative embodiments thereof. Since many vvariations and modifications or my invention will now be obvious to those skilled in the art, I prefer to be bound not by the speciiic disclosures herein contained but only by the appended claims.

I claim:

l. In a multi-pole circuit breaker, a plurality of fixed contacts, a plurality of movable contact arms carrying movable contacts, said arms having a circuit closed position in which their movable contacts engage said Xed contacts and a circuit open position in which said contacts are disengaged, a plurality of lll-shaped cradles, one oi said cradles having one end latched and pivotally mounted at its opposite end, the remaining cradies being only pivotally mounted at one end, a tie bar, said tie -bar rigidly connecting said cradles ior simultaneous motion, a plurality of springs, one end of said springs being secured to said movable arms and the opposite end of said springs being secured to said cradles at the apex or the U-shaped cradles, a pivotally mounted operating handle having a manually operable end on one side oi the pivot mounting and having a plurality of notches on the opposite end of the pivot mounting, said movable contact arms being pivotally mounted in said notches and extending substantially in the longitudinal direction oi said handle, with said movable contacts on the end opposite the pivotal mounting of said arms, the notches in said handle being on one side or said spring when said handle is in closed position so that said springs apply a closing force on said arms for operating said arms to circuit closed position, and the notches on said handle being on the opposite side of said springs when said handle is in open position so that said springs apply an opening force on said arms for operating said arms to circuit open position, a plurality of fault current responsive means, one of said means having a latch for latching the said cradle, a tripper bar, said tripper bar being operable by said fault current responsive means, an insulating housing, said housing having a plurality of recesses, insulating walls separating said recesses, each of said poles being mounted on one of said recesses, aligned openings in said separating Walls, said tie bar, said tripper bar and said longitudinal portion ci said handle extending through said openings ironi one end to the other 0i' said housing, means securing said cover plates at the said ends said housing.

2. ln a multi-pole circuit breaker, a plurality or contacts, a plurality of movable contact arms carrying movable contacts, said arms having a circuit closed position in which their movable contacts engage said fixed contacts and a circuit open position in which said contacts are disengaged, a single insulating housing, said housing having a plurality 0i' recesses, insulating Walls separating said recesses, each of said sets of contacts being mounted 0n one oi' said recesses, aligned openings in said separating Wall, cover plates, means securing said cover plates to said housing to close said recesses.

3. In a two-pole circuit breaker, a plurality of fixed contacts, a plurality or" movable contact arms carrying movable contacts, said arms having a circuit closed position in which their movable contacts engage said lined contacts and a circuit open position in which said contacts are disengaged, a plurality of U-shaped cradles, one oi said cradles having one end latched and pivotally mounted at its opposite end, the remaining cradles being only pivotally mounted at one end, a tie bar, said tie bar rigidly connecting said cradles for simultaneous motion, a plurality of springs, one end oi' said springs being secured to said movable arms and the opposite end of said springs being secured to said cradles at the apex 01' the U-shaped cradles, a pivotally mounted operating handle having a manually operable end on one side of the pivot mounting and having a plurality or notches on the opposite end of the pivot mounting, said movable contact arms being pivotally mounted in said notches and extending substantially in the longitudinal direction of said handle, with said movable contacts on the end opposite the pivotal mounting of said arms, the notches in said handle being on one side ci said spring when said handle is in closed position so that said springs apply a closing force on said arms for operating said arms to circuit closed position, and the notches on said handle being on the opposite side of said springs when said handle is in open position so that said springs apply an opening iorce on said arms for operating said arms to circuit open position, a plurality oi' fault current responsive means, one of said means having a latch for latching the said cradle, a tripper bar, said tripper bar being operable by said fault current responsive means, an insulating housing, said housing having two recesses, an insulating Wall separating the said two recesses, the said two poles being mounted in the said two recesses, said insulating wall having three openings, said tie bar extending through one of said openings from one end to the other of said housing, said tripper bar extending through the second of said openings from one end to the other of said housing and said longitudinal extension of said handle extending through the third of said openings from one end to the other of said housing, cover plates, means securing said cover plates at the said ends of said housing.

4. In a two-pole circuit breaker, a plurality or" fixed contacts, a plurality of movable contact arms carrying movable contacts, said arms having a circuit closed position in which their movable contacts engage said fixed contacts and a circuit open position in which said contacts are disengaged, a handle for manually operating said contact arms, a single insulating housing, said housing having two recesses, an insulating wall separating the said two recesses, the said two poles being mounted in the said two recesses, said insulating wall having a plurality oi openings, said tie bar, said tripper bar and said handle extending through said openings from one end to the other of said housing, cover plates, means securing said cover plates at the said ends of said housing.

5. In a three-pole circuit breaker, a plurality of fixed contacts, arplurality of movable contact arms carrying movable contacts, said arms having a circuit closed position in which their movable contacts engage said ixed contacts and a circuit open position in which said contacts are disengaged, a plurality of U-shaped cradles, one of said cradles having one end latched and pivotally mounted at its opposite end, the remaining cradles being only pivotally mounted at one end, a tie bar, said tie bar rigidly connecting said cradles for simultaneous motion, a plurality of springs, one end of said springs being secured to said movable arms and the opposite end of said springs being secured to said cradles at the apex of the U-shaped cradles, a pivotally mounted operating handle having a manually operable end on one side of the pivot mounting and having a plurality of notches on the opposite end of the pivot mounting, said movable contact arms being pivotally mounted in said notches and extending substantially in the longitudinal direction of said handle, with said movable contacts on the end opposite the pivotal mounting o1 said arms, the notches in said handle being on one side of said spring when said handle is in closed position so that said springs apply a closing force on said arms for operating said arms to circuit closed position, and the notches on said handle being on the opposite side of said springs when .said handle is in open position so that said springs apply an opening force on said arms for operating said arms to circuit open position, a plurality of fault current responsive means, one of said means having a latch for latching the said cradle, a tripper bar, said tripper bar being operable by said fault current responsive means to unlatch said latched cradle under fault current conditions, an insulating housing, said housing comprising two sections, one of said sections having two recesses, two of said poles being mounted in said two recesses, the second of said sections having one recess, the third of said poles being mounted in said one recess, said sections being mounted side by side to form said housing, the wall of said one recess section and the insulating wall of the said two recess section having a plurality of sets of aligned openings, said tie bar extending through one set of said openings from one end to the other of said housing, said tripper bar extending through another set of said openings from one end to the other of said housing, said longitudinal extension of said handle extending through another set of said openings from one end to the other of said housing, cover plates, means securing said sections together and securing said cover plates at the said ends of said housing.

6. In a three-pole circuit breaker, a, plurality of xed contacts, a plurality of movable contact arms carrying movable contacts, said arms having a circuit closed position in which their movable contacts engage said xed contacts and a circuit open position in which said contacts are disengaged, a handle for manually operating said contact arms, an insulating housing; said housing comprising two sections, one of asid sections having two recesses, an insulating wall separating the said two recesses, two of said poles being mounted in said two recesses, the second of said sections having one recess, the third of said poles being mounted in said one recess, said sections being mounted side by side to form said housing, the wall of said one recess section and the insulating wall of the said two recess section having a plurality of sets of aligned openings, said tie bar extending through one set of said openings from one end to the other of said housing, said tripper bar extending through another set of said openings from one end to the other of said housing, said handle extending through another set of said openings from one end to the other of said hcusing, cover plates, means securing said sections together and securing said cover plates at the said ends of said housing.

7. In a multi-pole circuit breaker, a plurality of ilxed contacts, a plurality of movable contact arms carrying movable contacts, said arms having a circuit closed position in which their movable contacts engage said fixed contacts and a circuit open position in which said contacts are disengaged, a plurality of U-shaped cradles, one of said cradles having one end latched and pivotally mounted at its opposite end, the remaining cradles being only pivotally mounted at one end, a tie bar, said tie bar rigidly connecting said cradles for simultaneous motion, a plurality of springs, one end of said springs being secured to said movable arms and the opposite end of said springs being secured to said cradles at the apex of the U-shaped cradles, a pivotally mounted operating handle having a manually operable end on one side of the pivot mounting and having a plurality of notches on the opposite end of the pivot mounting, said movable contact arms being pivotally mounted in said notches and extending substantially in the longitudinal direction of said handle, with said movable contacts on the end opposite the pivotal mounting of said arms, the notches in said handle being on one side of said spring when said handle is in closed position so that said springs apply a closing force on said arms for operating said arms to circuit closed position, and the notches on said handle being on the opposite side of said springs when said handle is in open position so that said springs apply an opening force on said arms for operating said arms to circuit open position, a plurality of fault current responsive means, one of said means having a latch for latching the said cradle, a tripper bar, said tripper bar being operable by said fault current responsive means to unlatch said latched cradle under fault current conditions, an insulatnig housing, said housing comprising a plurality of sections, some of said sections having two recesses and some having one recess, each lof said poles being mounted in one of said recesses, each of said sections being mounted side by side to form said housing, in-

sulatirig walls separating said recesses, sets of aligned openings in said separating walls, said tie bar extending through one set of said openings from one end to the other of said housing, said tripper bar extending through another set of said openings from one end to the other of said housing and said longitudinal extension of said handle extending through the third of said openings from one end to the-other of said housing, cover plates, means securing said sections together and said cover plates at the said ends of said housing 8. In a multi-pole circuit breaker, a plurality of fixed contacts, a plurality of movable contact arms carrying movable contacts, said arms having a circuit closed position in which their movable contacts engage said iixed contacts and a circuit open position in which said contacts are disengaged, a plurality of U-shaped cradles, said cradles having one end latched and pivotally mounted at its opposite end, a plurality of springs, one end of said springs being secured to said movable arms and the opposite ends of said springs being secured to said cradles at the apex of the U-shaped cradles, a pivotally mounted operating handle having a manually operable end at one side of the pivot mounting and having a plurality of notches on the opposite end of the pivot mounting, said movable contact arms being pivotally mounted in said notches and extending substantially in the longitudinal direction of said handle with said movable contacts on the opposite end of said pivotal mounting of said arms, the notches in said handle being on one side of said spring when said handle is in closed position so that said springs apply a closing force on said arms for operating said arms to circuit closed position, and the notches of said handle being on the opposite side of said springs when said handle is in open position so that said springs apply an opening force on said arms for operating said arms to a circuit open position, fault current responsive means having a latch for latching said cradle, an insulating housing, said housing having a plurality of recesses, insulating walls separating said recesses, each of said poles being side mounted on one side of said recesses, and means securing said cover plates to the sides of said housing.

9. In a two pole circuit breaker, a plurality of fixed contacts, a plurality of movable contact arms carrying movable contacts, said arms having a circuit closed position in which their movable contacts engage said movable contacts and a circuit open position in which the said contacts are disengaged, U-shaped cradle means having one end latched and pivotally mounted at its opposite end, a plurality of springs, one end of said springs being secured to said movable arms and the opposite end of said springs being secured to said U-shaped cradle means at the apex thereof, pivotally mounted operating handle means having a manually operable end on one side of the pivot mounting and having a plurality of notches on the opposite ends or" the pivot mounting, said movable contact arm being pivotally mounted in said notches and extending substanially in the longitudinal direction or said handle with said movable contacts on the end opposite the pivotal mounting of said arms, the notches in said handle being on one side of said spring when said handle is in closed position so that said springs apply a closing force on said arms for operating said arms to circuit closed position, the notches on said handle being on the opposite sides of said springs when said handle is in open position so that said springs apply an opening force on said arms for operating said arms to circuit open position, fault current responsive means having a latch for latching said U-shaped cradle means, a single insulating molded housing, said housing having two recesses and an insulated Wall separating the said tivo recesses, the said two poles being side mounted in the said two recesses, said insulating wall electrically insulating said two poles from each other, cover plates, means securing said cover plates to said housing to thereby cover said poles and said recesses.

l0. In a three pole circuit breaker, a plurality of xed contacts, a plurality or" movable contact arms carrying movable contacts, said arms hava circuit closed position in which their movable contacts engage said iixed contacts and a circuit open position in which said contacts are disengaged, U-shaped cradle means having one end latched and pivotally mounted at the opposite ends, a plurality or springs, one end of said springs being secured to said movable arms and the opposite end of said springs being secured at the apex of said U-shaped cradle means, pivotally mounted operating handle means having a manually operable end on one side of the pivot mounting and having a plurality of notches on the opposite ends of the pivot mounting, said movable contact arms being pivotally mounted in said notches and extending substantially in the longitudinal direction of said handle, said movable contacts on the ends opposite the pivotal mounting of said arms, the notches in said handle being on one side of said spring when said handle is in closed position so that said springs apply a closing force on said arms for operating said arms to circuit closed position, the notches in said handle being on the opposite side of said springs when said handle is in open position so that said springs apply an opening force on said arms for operating said arms to circuit open position, fault current responsive means having a latch for latching said U-shaped cradle means, said fault current responsive means effective to unlatch said U-shaped cradle means under fault current conditions, an insulating housing comprising two sections, one of said housing sections having two recesses, an insulating wall separating said two recesses, two of said poles being side mounted in said two r cesses, the second oi said housing sections having one recess, the third of said poles being mounted in said last mentioned recess, said sections being mounted side by side to form a pancaked assembly, cover plates, means securing said sections together and securing said cover plates at the end of said housing.

ll. In a three pole circuit breaker, a plurality of fixed contacts, a plurality of movable contact arms carrying movable contacts, said arms having a circuit closed position in which their movable contacts engage said fixed contacts and a circuit open position in which said contacts are disengaged, handle means or manually operating said contacts, a single insulating housing, said housing comprising two sections, one of said housing sections having two recesses with an insulating wall separating said two recesses, two of said poles being mounted in said two recesses, a second of said housing sections having one recess, the other of said poles being mounted in said one recess, said sections being mounted side by side to form said housing, cover plates, means securing said sections together and securing said cover plates at the said ends of said housing.

12. In a multi-pole circuit breaker, a plurality of fixed contacts, a plurality of movable Contact arms carrying said movable contacts, said arms having a circuit closed position in which their movable contacts engage said xed contacts and a circuit open position in which said contacts are disengaged, handle means for manually operating said contact arms, an insulating housing, said housing having two recesses and an insulating Wall, said insulating wall separating said two re` cesses of said housing, a pole of said circuit breaker being mounted in each of said two recesses, cover plates, said cover plates secured at the ends of said housing to cover said recesses and said poles.

13. In a two pole circuit breaker, a plurality of fixed contacts, a plurality of movable contact arms carrying movable contacts, said arms having a circuit closed position in which their Inovable contacts engage said nxed contacts and a circuit open position in which said contacts are disengaged, handle means :for manually operating said contact arms, a single insulating molded housing, said single insulating molded housing having an insulating wall and two recesses, said insulating wall separating said two recesses of said single insulating molded housing, Said two poles being mounted in said two recesses, two cover plates, means securing said two cover plates to said housing to cover said recesses and said poles.

WILLIAM H. EDMUNDS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 23,188 I-Iumpage Jan. 10, 1950 1,642,142 Cook Sept. 13, 1927 2,367,382 Taylor Jan. 16, 1945 2,502,537 Speck Apr. 4, 195) 

